What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Np203 problems please help

76k5blazerr

76k5blazerr

Git-er-dun
 Premium
Joined
Nov 13, 2013
Posts
1,587
Reaction score
744
Location
North Carolina
well guys I think the 203 in my blazer is on its way out. Here's what is going on. When I accelerate off of a stop I have to accelerate very slowly because of you gas it hard you get clunking, almost like the t case chain/gears are slipping, and also when your going uphill when it's under a load it makes a grinding noise almost like a groan and when it groans you can feel it in the shifters for the t case. If all of this is coming from the tcase there should be metal shavings in the fluid right? I'm gonna check on that ASAP. What do you guys think is going on? I appreciate any and all answers I can get. Thanks yall.

PS: here is the parts I have personally replaced recently.

U joints front and rear shafts.
Tranny rebuild (2000 miles ago)
Tranny mounts

And the parts I have laying on my workbench that need to go In:
Rear leaf spring and shackle bushings
U bolts
Rear pinion seal
 
those 203 chains are known to stretch and slap the case but it sounds like you may have some other issues.
 
Yes it's part time converted, u joints are good. So you think it's the chain? Anything else? Hopefully some t case people will have some input on this.
 
76k5blazerr said:
Yes it's part time converted, u joints are good. So you think it's the chain? Anything else? Hopefully some t case people will have some input on this.
Click to expand...

The chain is the common issue with them, nobody will know for sure what wrong with yours. You need to crack it open and look.

FWIW I just tore out my 203 for a noisy chain :whistle:
 
I had a NP-203 in a 74 K2500 I bought with a 454 & Th350,and if you hit the gas a bit too much at a standstill,the T-case would make a shuddering sensation like the chain was skipping over the sprockets..

I made sure the linkage was adjusted right and it was,so I decided to swap in a NP-205 I already had from another truck,rather than deal with the NP-203...

I was told by a local transmission shop they saw a lot of 203's that had the "part time" kits installed,and they had cheap powdered metal gears,that failed rapidly,and could cause the same type of thing...

I still have that 203 sitting in a shed,I never did try investigating to see if it was the chain or not--spinning it by hand it feels like it doesn't have much slop in it ,so it may have been "converted" or had issues with the third differential in the tailshaft...I kept it in case I ever decided to make a doubler,but its been 20 years and I have no plans to use it now..but the minute I scrap it I'll probably need it for parts another truck,so I've resisted doing so..
 
That shuddering when hitting the gas sounds like the same thing going on with mine. is there a time when I'm gonna hit the gas and it just won't go anywhere or will it just stAy slightly worn out but never go out completely? And am I damaging anything other than the tcase by driving it still? Cause it's my DD.
 
A loose chain will eventually strip the sprocket teeth and put a ton of metal bits in the oil,which wont do anything in there are good..if you baby it it might last awhile,but the longer its driven that way,the more damage everything else inside will suffer too...

I'd just start looking on craigslist or at salvage yards for another transfer case and slap it in...yours might be too ground up to bother repairing if its been this way for long..cheaper & easier to just swap another one in it..
I dont even know if you can still get a chain for a 203,I read a post awhile back somewhere saying they were discontinued long ago,and if you can find one,they want 150+ bucks for it...you can probably buy another good used 203 for that..
 
Well The plan for this truck is to drive it only till I can afford another truck to DD then restore this one, and I'm about to buy a parts truck for 500, another 76 k5. It comes with a 203 so I think I'll swap that one in as soon as I can get it. Then hopefully it will get me through another couple months. Thanks yall, if you guys think of anything else that could be wrong or have anything else to ad please go right ahead.
 
pickup a Harbor Freight trans jack, you can swap it out pretty easily by yourself.

Here's a pic of my POS 203 coming out....


IMG_7450sm_zpsbb47a706.jpg
 
Yah I'm familiar with pulling them. I used a cradle kinda thing that I welded up and welded to my floor jack when I dropped the t case and tranny as a unit about a year ago when I had the tranny rebuilt. Then used an actual tranny jack to reinstall them because I had access to a lift.
 
If it doesn't already have a magnetic drain plug,it wont hurt to add one,and change the oil in it ,the magnet will keep the metallic bits from being circulated thru the case...that'll help it live till you can swap it out..that and avoiding any jack rabbit starts from stop signs and red lights!..
 
Where can I get a mentallic drain plug, I've never heard of those. Sound cool though. And yeah I'm sure everyone who drives behind me at red lights and stop signs thinks I'm a **** but nope, if only they knew I'm just trying to save my poor np203.
 
Most any good parts store sells the magnetic drain plugs,you'll probably have to take the original one out and match it up,it is probably a tapered pipe thread plug most likely.

I dont know what size the drain plug is--I could look at the one on mine,if the shed wasn't 100 feet behind my house,with 6 foot snow drifts blocking the doors from opening...:doah:
 
I'll check on it next time I'm over at pep boys. I seem to be in there at least once or twice a week. Have fun with the snow. Still 50 degrees down here lol.
 
You must log in or register to reply here.

Latest Posts

Top Bottom